1. Field of the Invention
The invention relates to a liquid crystal display (LCD) device, and more particularly, to a liquid crystal display module (LCDM) having a simple structure.
2. Discussion of the Related Art
The liquid crystal display module (LCDM) is widely used as a display device for a notebook personal computer (NTPC). The LCDM includes a liquid crystal panel and a driving circuit unit for driving the liquid crystal panel. The liquid crystal panel includes a first substrate and a second substrate and a layer liquid crystal material interposed therebetween. The liquid crystal material is divided into cells arranged in a matrix. Switching elements for controlling signals applied to the liquid crystal cells are formed on one of the first and second substrates.
The liquid crystal panel does not have a light source therein. Thus, the LCDM requires a light source that projects light into the liquid crystal panel. The light source for the LCDM can be a backlight unit that includes a lamp.
FIG. 1 is a cross-sectional view of the related art LCDM. As shown in FIG. 1, the LCDM includes a liquid crystal panel 1, a main frame 5, a top frame 12, and a bottom frame 14. The liquid crystal panel 1 includes first and second substrates (not shown) facing each other with a layer of liquid crystal material (not shown) therebetween. First and second polarization plates 42 and 44 are attached onto outer surfaces of the first and second substrates, respectively. A switching element, such as a thin film transistor (TFT), is formed on the first substrate. The top frame 12 covers edges of the liquid crystal panel 1 and sides of the main frame 5 such that the top frame 12 can support and protect the edges of the liquid crystal panel 1 and the sides of the main frame 5. The main frame 5 is combined with the top frame 12 by an affixing element, such as a screw.
Generally, the main frame 5 is fabricated using a mold. However, to provide television or monitor with high brightness, the main frame 5 is formed of a metallic material, such as aluminum (Al), having an excellent heat resistant property. The liquid crystal panel 1 is disposed on the main frame 5. The bottom frame 14 covers back edges of the main frame 5, so that the bottom frame 14 is combined with the main frame 5, the top frame 12 and a backlight unit to form a module.
A backlight unit of the LCDM includes a light emitting diode (LED) lamp 32 as a light source, a light guide plate 34 that disperses the dot light source of the LED lamp 32 into planar light, a reflective sheet 36 disposed under the light guide plate 34 and an optical sheet, including a prism sheet 24 and a diffusion sheet 22, stacked on the light guide plate 34. The LED lamp 32 is disposed at a side of the light guide plate 34. The light from the LED lamp 32 is projected into the side of the light guide plate 34 and reflected by the reflective sheet 36 to be changed into planar light. Then, the planar light is projected into the liquid crystal panel 1. The backlight unit may further include a lamp housing (not shown) surrounding the LED lamp 32 to increase a light efficiency. The lamp housing is formed of a material having a high optical reflectance.
The light guide plate 34 having a predetermined thickness includes an inclined rear surface and a flat front surface. The reflective sheet 36 reflects the light provided thereon from the rear surface of the light guide plate 34 back into the light guide plate 34 such that light projects from the front surface. As a result, light loss is reduced due to the reflective sheet 36.
FIG. 2 is a perspective view of the related art LED lamp array. FIG. 3 is a perspective view showing a rear side of the related art LCDM. Referring to FIGS. 2 and 3 with FIG. 1, a plurality of LED lamps 32 are arranged on a flexible printed circuit board (FPCB) 31. The FPCB 31 with the LED lamps can be referred to as the LED lamp array 30. The FPCB 31 is located on an inner side surface of the bottom frame 14 and extends onto an outer side by passing through a hole H in the side surface of the bottom frame 14. An exterior circuit connection part 33 is formed at an end of the FPCB 31. More specifically, the exterior circuit connection part 33 passes through the hole H and is connected to an exterior circuit connection part 33, such as a backlight unit controlling circuit (not shown), for applying control signal or operating power to the LEDs 32.
Unfortunately, when a position of the exterior circuit connection part 33 in the LED lamp array 30 is changed, a position of the hole H also has to be changed. However, since changes to the mold for fabricating the bottom frame 14 is required for changes in the position of the exterior circuit connection part 33, production costs increase. Moreover, production time increases when such changes are implemented.